Core for a mold



Jan. 12, 1965 E. J. LEE 3,164,877

CORE FOR A MOLD Filed Sept. 1'7, 1962 v 2 Sheets-Sheei 1 3; l2 9 Q3 20 r2 ,u x\\\\ 25"- 25 .s 'Q 2 4 3o 'l i 3| 3 l 2| 22 Qo' 55 k 3% \b% I l u -I 54 INVENTOR.

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ATToRN EVS E. J. LEE

CORE FOR A MOLD Jan. l2, 1965 2 Sheets-Sheet 2 Filed Sept. 17, 1962 INVENTOR. 0 w/H J. LEE

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ATTOQNEYS a y areas?? Ice Patenteddan. 12, 1965 3,164,877 CORE FOR A MLD Edwin J. Lee, Eulierton, Calif., assignor to American Pipe and Construction Co., Los Angeles, Caiif., a corporation of California Filed Sept. 17, i962, Ser. No. 224,633 t 7 Claims. (Ci..25 l28) This invention has to do with the cores of molds used in the manufacture of large poured concrete pipe sections and particular-ly with a gate construction foresuch cores.

Cores for molds used in making large sized concrete pipe sections are conventionally made of heavy gauge sheet metal. To enable the core to be stripped from the cast pipe body,rthe core is split longitudinally at one side and hinge means providedalong lthe Vsplit providing a gate which can be opened to partially collapse the core. Wedges are used in conjunction with wedge receiving brackets for holding the core in its `normal position with the gate-closed.

Due to the ilexibility of the sheet metal, the large sizes involved and the type of gate used, the cores tend to form an ellipse when collapsed, making it very difcult to remove them from the cast body of concrete. Constructions heretoforeused in hinging the core gate were disadvantageous in that they limited the amountof collapse or overlap of the adjacent edges of the core along the split. v

`An lobject of the invention is to providea novel core gate construction-which allowsl the core to be collapsed sufficiently tol enable it to be easily removed or stripped from the cast body of the concrete pipe section. 1

More particularly it is an object to provide aY novel hinge construction for` a core gate.

Another object -is to provide a novel keeper and wedge construction for use in holding the core in fully expanded position with the gate or joint closed which permits the gate to be opened` relatively wide when the wedges are withdrawn.

These and other objects will be apparent from the drawings and the following description. Referring to the drawings: j

FIG. 1 Vis an elevational view partly broken away showing a core embodying the invention;

FIG. 2 is a fragmentary sectional view on line 2 2 of FIG. 1, but on a larger scale;

FIG. 3 is a fragmentary sectional View on line 3 3 of FIG. l, on the same scale as FIG. 2;'

FIG..4'is a fragmentary sectional view on line 4 4 of FIG. 1, on the same scaleas FIG. 2; l

FIG. 5 is a View similar to FIG. 4 but showing' the parts with the gate in open position; Y

FIG. 6 is a fragmentaryY elevational view on line 6 6 l of FIG. 2; i

FIG. 7 is a fragmentary elevational view on line 7 '77 of FIGfS; and Y f v FG. 8 is a fragmentary elevational view on `line 8 8 of FIGA. l More'particularly describing the invention, lnumeral 11 designates generally a core or core member for a mold suchv as used in the manufacture of large sizedY concrete pipe sections by the method wherein the concrete is poured into thek mold. y The core comprisesa cylindrical body 12 of sheet metalof suitable gauge which is provided with a slot 14 defined by marginal edges 15 and-,'16 of the body 12,. Thus the sheet metal body 12 substantially forms a"cylinder, lacking onlythe portion between the two edges 1Sfand 16. In orderV to vfill this space and reinforee'theV edges,V a reinforcing substantially rigid gate rstrip 19 is provided along the edge 15 and a similar stripV sheet metal of the body 12 and are recessed at 19' and 20' respectively to receive the edge portions of the body. They are preferably welded together.

The two strips 19 and 20 are provided with `comple,- mentary abutting beveled faces 21 and 22 and preferably a seal is provided therebetween and this has been shown as a rubber or plastic strip 23 in a groove 24 provided in surface 21.

The two marginal edge portions ofthe body 12 and the strips 19 and 20 are hingedly connected by aplurality of hinges 2S spaced along the core gate axially of the core. Each hinge comprises a pivot bar 27 which is welded or otherwise rigidly attached to the strip 20. The bar projects substantially across the other strip 19 and is piv, otally mounted at 28- on a pair of links 29 whichV are carried on a shaft 30. The shaft is journaled in a plurality of bearings 3l provided along the core as best shown in FIG. 1. Y Y A Y The core is also provided with a plurality of wedge assemblies, designated 32, which arespaced axially along the core gate. Each of these includes a wedge bar 33 which is welded or otherwise rigidly attached to the strip 26. This bar has a flat outer surface 34 which extends across the inner surface of the strip 19, it being recessed at 35 to freely receive the aforementioned shaft 30. As sociated with each bar 33 is a wedge receiving bracket 36 .which includesy a pair of similarly shaped, parallel spaced plates 37 Welded to the core body 12 and to strip 19, the plates being recessed at 3S to tit the strip 19. These plates are connected at their inner end portion by a cross bar 40 Vand are spaced apart sufficiently so as to slidingly receive thewedge bar 34. The bracket also receives, a wedge 42, having a head 43, and a body 44 provided with a straight edge 45 and an inclined edge46which converges with respect to edge 45. The wedge is inserted'between the inner edge 47 of the wedge bar and the cross bar 40 to hold the parts in the position in which they are shown in FIG. 3.

It is a particular feature of the bracket 36 that the forward edges 48 thereof Vare recessed, being formed by the edge portions 49 and 50 continuations of which would form an obtuse angle, and a rounded intermediate portion 51. The portion 51 is thus disposed rearwardly of the joint and rearwardlyv with respect to bar 40, and, as will later appear, this'permits maximum opening of the joint.

Certain of the pivot bars 18 are provided with special links 54 in place of the links 29. The links 54 are pro-v vided with a handle 55 which extends angularly inward from end portions 56 of the links 5'4.

When the Wedges 42 are in place as shown in FIG. 3, the mold core is ready for use. After the molding oper-l ation has been completed and the concrete has hardened v suiiiciently to .permit stripping of the core, the wedges 42 are removedand the core collapsed by moving the handle members from the position of FIG. 4 to that of FIG. 5.

Referring to` the latter figure, it will be seen that the` core is thus collapsed substantially since the strip 20 is broughtfj inside of strip 19 and in Aoverlapping relation thereto.

20 along the edge 16. .Thesestrips are thicker than the The limiting factor* in the amount of this movementjy is 'v ,the-forward edges of the platesf37 which lmake up'V the wedge receiving bracket, andas previously 'pointed out,

j these arejrecessed to permit maximum movement of the parts.

Although I have shown and described a preferred form of 'my invention, I contemplate that various changes and f modifications can be made therein without departing from. the invention, the scope of which is determined by the claims which follow;

I claim:

1. A core for a mold used in casting large poured con-Vv crete pipe sections, comprising a cylindrical body ofheavy gauge sheet metal having a longitudinal parting from end to end, a substantially rigid gate strip secured to each marginal edge of the body along the parting, said gate strips being thicker than said cylindrical body and having abutting complementary edges, a plurality of pivot bars fixed to one of said gate strips at spaced intervals therealong, said pivot bars each extending across the other of said gate strips and in abutment with the inner surface thereof, a plurality of links pivotally secured to said cylindrical body along an axis extending longitudinally of the core and spaced circumferentially beyond said other gate strip, a pivotal connection between each link and one of said pivot bars at the end portion of the bar nearest said axis, a plurality of wedge bars xed to said one o f said gate strips at spaced intervals therealong, said wedge bars each extending across said other of said gate strips and in abutment with the inner surface thereof, a Wedgereceiving bracket mounted on said body beyond said other gate strip for each Wedge bar, each bracket having an opening slideably receiving a wedge bar and adapted to receive a Wedge, and a wedge removably mounted in the opening of each bracket and having a face abuttingly engaging the Wedge bar.

2. The core set forth in claim 1 in which each bracket is formed to provide a recessed edge facing Said one gate strip.

3. The core set forth in claim 1 in which said links are pivotally secured to the body by a common shaft extending axially of the body and journaled thereon, said links being mounted on the shaft.

4. The core set forth in claim 1 in which a seal is pro-V vided between the abutting edges of the gate strips.

5. The core set forth in claim 1 in which a handle is provided on certain of said links.

6. In a core for a mold used in casting large poured concrete pipe'sections, having a cylindrical body provided with an axial gate and hinge means for collapsing the core by opening the gate and disposing the adjacent edges l of the core in overlapping relation, means for releasably securing said gate closed, comprising a plurality of Wedge bars spaced axially of the core fixed to said body along one side of the gate and extending across the gate and the other sides thereof, a wedge bracket for each wedge bar, each bracket being fixed to the core at the other side of the gate and spaced back from the line of parting, each bracket providing a slot receiving a wedge bar, and a wedge received in said slot wedged between said wedge bar and the inner end of the slot, said brackets each being so constructed and arranged that the edges of the bracket facing the gate recede from the inner end of the slot outwardly of the core with respect to a plane extending radially of the core and through the line of parting of the gate, whereby to permit maximum overlap of the core edges when the gate is opened.

7. In a corerfor a mold used in casting large poured concrete pipe sections, comprising a cylindrical body of heavy gauge sheet metal having a longitudinal parting from end to end, a substantially rigid gate strip secured to each marginal edge of the body along the parting, said gate strips being thicker than said cylindrical body and having abutting complementary edges, a plurality of pivot bars lixed to one of said gate strips at spaced intervals therealong, said pivot bars `each extending across the other of said gate strips and in abutment with the inner surface thereof, a plurality of links pivotally secured to said cylindrical body along an axis extending longitudinally of the core and spaced circumferentially beyond said other gate strip, and a pivotal connection between each link and one of said pivot bars at the end portion of the bar nearest said axis.

References Cited in the tile of this patent lUNITED STATES PATENTS 

7. IN A CORE FOR A MOLD USED IN CASTING LARGE POURED CONCRETE PIPE SECTIONS, COMPRISING A CYLINDRICAL BODY OF HEAVY GAUGE SHEET METAL HAVING A LONGITUDINAL PARTING FROM END TO END, A SUBSTANTIALLY RIGID GATE STRIP SECURED TO EACH MARGINAL EDGE OF THE BODY ALONG THE PARTING, SAID GATE STRIPS BEING THICKER THAN SAID CYLINDRICAL BODY AND HAVING ABUTTING COMPLEMENTARY EDGES, A PLURALITY OF PIVOT BARS FIXED TO ONE OF SAID GATE STRIPS AT SPACED INTERVALS THEREALONG, SAID PIVOT BARS EACH EXTENDING ACROSS THE TOHER OF SAID GATE STRIPS AND IN ABUTMENT WITH THE INNER SURFACE THEREOF, A PLURALITY OF LINKS PIVOTALLY SECURED TO SAID CYLINDRICAL BODY ALONG AN AXIS EXTENDING LONGITUDINALLY OF THE CORE AND SPACED CIRCUMFERENTIALLY BEYOND SAID OTHER GATE STRIP, AND A PIVOTAL CONNECTION BETWEEN EACH LINK AND ONE OF SAID PIVOT BARS AT THE END PORTION OF THE BAR NEAREST SAID AXIS. 